1. Field of the Invention
The instant invention relates to a method of pretreatment of inorganic materials, such as glass, fibers with compounds selected from the class of N-silyl substituted 1-silyl-2-azacycloaklanes. The instant invention also relates to a process for making composite materials in which said pretreated inorganic materials are incorporated.
2. Prior Art
Various silane compounds have previously been employed as coupling agents for use in reinforced reaction injection molding (RRIM) technology. For instance, U.S. Pat. No. 4,582,887 discloses the use of chlorosilanes and isocyanate silanes as coupling agents in the practice of this technology. U.S. Pat. No. 4,607,090 discloses the use of epoxy silanes for the same function.
Zhurnal Obshchei Khimii, Volume 42, No. 4, pp. 858-862 has reported the possible formation of minor amounts of 1,1,1-triethoxy-N-[3-(triethoxysilyl)propyl]silylamine during the hydrosilylation of allylamine. However, no mention of the cyclic derivatives was reported.
The Journal of Organic Chemistry Vol. 34, 3676 (1969) has reported the synthesis of the cyclic structure 1,1-diethoxy-2-(trimethylsilyl)-1-sila-2-azacyclopentane. This compound, however, lacks a hydroxyzable moiety and therefore would not perform satisfactorily to reinforce or couple in RRIM compositions due to trimethylsilylation of siliceous surfaces, reducing their reactivity with and/or wetting by typical RIM polymer matrices and also reducing their reactivity to subsequent treatments by conventional silane coupling agents. Therefore, subsequent applications of conventional coupling materials, such as 3-aminopropyltrimethoxysilane, to the glass fibers, will result in diminished bond strength, thereby making the use of 1,1-diethoxy-2-(trimethylsily)-1-sila-2-azacyclopentane undesirable in RRIM applications.